Organometallic solution based high resolution patterning compositions

ABSTRACT

Organometallic solutions have been found to provide high resolution radiation based patterning using thin coatings. The patterning can involve irradiation of the coated surface with a selected pattern and developing the pattern with a developing agent to form the developed image. The patternable coatings may be susceptible to positive-tone patterning or negative-tone patterning based on the use of an organic developing agent or an aqueous acid or base developing agent. The radiation sensitive coatings can comprise a metal oxo/hydroxo network with organic ligands. A precursor solution can comprise an organic liquid and metal polynuclear oxo-hydroxo cations with organic ligands having metal carbon bonds and/or metal carboxylate bonds.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 17/830,535 to Meyers et al, filed Jun. 2, 2022, entitled“Organometallic Solution Based High Resolution Patterning Compositions,”which is a continuation of co-pending U.S. patent application Ser. No.16/536,768 to Meyers et al., filed Aug. 9, 2019, entitled“Organometallic Solution Based High Resolution Patterning Compositions,”which is a continuation of U.S. patent application Ser. No. 16/007,242,now U.S. Pat. No. 10,416,554, to Meyers et al., filed Jun. 13, 2018,entitled “Organometallic Solution Based High Resolution PatterningCompositions,” which is a continuation of U.S. patent application Ser.No. 14/983,220, now U.S. Pat. No. 10,025,179, to Meyers et al., filed onDec. 29, 2015, entitled “Organometallic Solution Based High ResolutionPatterning Compositions,” which is a continuation of U.S. patentapplication Ser. No. 13/973,098, now U.S. Pat. No. 9,310,684, to Meyerset al. filed on Aug. 22, 2013, entitled “Organometallic Solution BasedHigh Resolution Patterning Compositions,” all of which are incorporatedherein by reference.

STATEMENT AS TO GOVERNMENT RIGHTS

This invention was made with government support under grant IIP-0912921awarded by the U.S. National Science Foundation. The Government hascertain rights in the invention.

FIELD OF THE INVENTION

The invention relates to radiation based methods for the performance ofpatterning materials using an organometallic coating composition. Theinvention further relates to precursor solutions that can be depositedto form organometallic coatings that can be patterned with very highresolution with radiation and to the coated substrates and coatingsformed with the precursor solutions before and after patterning.

BACKGROUND OF THE INVENTION

For the formation of semiconductor-based devices as well as otherelectronic devices or other complex fine structures, materials aregenerally patterned to integrate the structure. Thus, the structures aregenerally formed through an iterative process of sequential depositionand etching steps through which a pattern is formed of the variousmaterials. In this way, a large number of devices can be formed into asmall area. Some advances in the art can involve that reduction of thefootprint for devices, which can be desirable to enhance performance.

Organic compositions can be used as radiation patterned resists so thata radiation pattern is used to alter the chemical structure of theorganic compositions corresponding with the pattern. For example,processes for the patterning of semiconductor wafers can entaillithographic transfer of a desired image from a thin film of organicradiation-sensitive material. The patterning of the resist generallyinvolves several steps including exposing the resist to a selectedenergy source, such as through a mask, to record a latent image and thendeveloping and removing selected regions of the resist. For apositive-tone resist, the exposed regions are transformed to make suchregions selectively removable, while for negative-tone resist, theunexposed regions are more readily removable.

Generally, the pattern can be developed with radiation, a reactive gas,or liquid solution to remove the selectively sensitive portion of theresist while the other portions of the resist act as a protective etchresistant layer. Liquid developers can be particularly effective fordeveloping the image. The substrate can be selectively etched throughthe windows or gaps in the remaining areas of the protective resistlayer. Alternatively, desired materials can be deposited into theexposed regions of the underlying substrate through the developedwindows or gaps in the remaining areas of the protective resist layer.Ultimately, the protective resist layer is removed. The process can berepeated to form additional layers of patterned material. The functionalinorganic materials can be deposited using chemical vapor deposition,physical vapor deposition or other desired approaches. Additionalprocessing steps can be used, such as the deposition of conductivematerials or implantation of dopants. In the fields of micro- andnanofabrication, feature sizes in integrated circuits have become verysmall to achieve high-integration densities and improve circuitfunction.

SUMMARY OF THE INVENTION

In a first aspect, the invention pertains to a method for patterning asubstrate with radiation, the method comprising the steps of irradiatinga coated substrate along a selected pattern to form an irradiatedstructure with a region of irradiated coating and a region withun-irradiated coating and selectively developing the irradiatedstructure to remove a substantial portion of the irradiated coating orof the un-irradiated coating to form a patterned substrate. The coatedsubstrate generally comprises a coating that comprises a metaloxo-hydroxo network with organic ligands with a metal carbon bondsand/or with metal carboxylate bonds.

In a further aspect, the invention pertains to a coated substratecomprising a radiation sensitive coating having an average thickness ofno more than about 10 microns and a thickness variation of no more thanabout 50% from the average at any point along the coating, the coatingcomprising metal oxo-hydroxo network with metal cations having organicligands with a metal carbon bonds and/or with metal carboxylate bonds.

In another aspect, the invention pertains to a patterned substratecomprising a substrate with a surface and a first coating at selectedregions along the surface and absent at other regions along the surface.Generally, the first coating comprises metal oxo-hydroxo network andorganic ligands with metal cations having organic ligands with a metalcarbon bonds and/or with metal carboxylate bonds. Alternatively, thefirst coating is soluble in at least some organic liquids, or the firstcoating is soluble in aqueous bases.

In additional aspects, the invention pertains to a precursor solutioncomprising an organic liquid and from about 0.01M to about 1.4M metalpolynuclear oxo/hydroxo cation with organic ligands having a metalcarbon bonds and/or with metal carboxylate bonds, the precursor solutionhaving a viscosity from about 0.5 centipoises (cP) to about 150 cP. Theorganic liquid can have a flash point of at least 10° C. and a vaporpressure at 20° C. less than about 10 kPa.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a radiation patternedstructure with a latent image.

FIG. 2 is a side plan view of the structure of FIG. 1 .

FIG. 3 is a schematic perspective view of the structure of FIG. 1 afterdevelopment of the latent image to remove un-irradiated coating materialto form a patterned structure.

FIG. 4 is a side view of the patterned structure of FIG. 3 .

FIG. 5 is a schematic perspective view of the structure of FIG. 1 afterdevelopment of the latent image to remove irradiated coating material toform a patterned structure.

FIG. 6 is a side view of the patterned structure of FIG. 5 .

FIG. 7 is a side plan view of the patterned structure of FIGS. 3 and 4following etching of the underlayer.

FIG. 8 is a side plan view of the structure of FIG. 7 following etchingto remove the patterned, condensed coating material.

FIG. 9 is a side plan view of a “thermal freeze” double patterningprocess flow. The process shown in FIGS. 1-3 is repeated after a bakethat renders the first layer insoluble to the second layer.

FIG. 10A is a plot of the autocorrelation scattering intensity decayversus time of a precursor solution with monobutyltin oxide hydrate.

FIG. 10B is a histogram of the calculated mass averaged particle sizedistribution of a precursor solution comprising monobutyltin oxidehydrate in 4-methyl-2-pentanol.

FIG. 11A is a scanning electron micrograph of negative tone patternedcoating with 18 nm wide lines on a 36 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with a 30kV electron beam at a dose of 1191/μC/cm², and developed in4-methyl-2-pentanol.

FIG. 11B is a scanning electron micrograph of negative tone patternedcoating with 18 nm wide lines on a 36 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with a 30kV electron beam at a dose of 1191/μC cm², and developed in ethyllactate.

FIG. 11C is a scanning electron micrograph of negative tone patternedcoating with 18 nm wide lines on a 36 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with a 30kV electron beam at a dose of 1191 μC/cm², and developed in propyleneglycol monomethyl ether (PGMEA).

FIG. 11D is a scanning electron micrograph of negative tone patternedcoating with 18 nm wide lines on a 36 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with a 30kV electron beam at a dose of 1191 μC/cm², and developed in n-butylacetate.

FIG. 12A is a scanning electron micrograph of a negative tone patternedcoating with 22 nm wide lines on a 44 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with EUVprojection lithography with a 13.5 nm radiation at a dose of 101 mJ cm⁻²and developed with PGMEA.

FIG. 12B is a scanning electron micrograph of a negative tone patternedcoating with 18 nm wide lines on a 36 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with EUVprojection lithography with 13.5 nm radiation at a dose of 101 mJ cm⁻²and developed with PGMEA

FIG. 13 is a plot of relative hydrocarbon concentration versus electronbeam dose as calculated from FTIR transmission measurements of C-Hstretching mode absorbance for a coating material formed withmonobutyltin oxide hydrate.

FIG. 14 is a scanning electron micrograph of positive tone patternedcoating with 30-nm wide lines and a 60 nm pitch in a coating materialformed with monobutyltin oxide hydrate following irradiation with a 30kV electron beam at a dose of 511 μC/cm² and development with 2.38%TMAH.

FIG. 15A is a scanning electron micrograph of negative-tone patternedcoating with 18 nm wide lines on a 36 nm pitch and a line—widthroughness (LWR) of 2.78 nm in a coating material formed withmonobutyltin oxide hydrate following irradiation with a 30 kV electronbeam at a dose of 1191 μC/cm² of a film that was deposited from afreshly prepared precursor solution and immediately exposed anddeveloped in PGMEA.

FIG. 15B is a scanning electron micrograph of negative-tone patternedcoating with 18 nm wide lines on a 36 nm pitch and a LWR of 2.87 nm in acoating material formed with monobutyltin oxide hydrate followingirradiation with a 30 kV electron beam at a dose of 1191 μC/cm² of afilm that was deposited from a precursor solution aged 39 days atroom-temperature and then immediately exposed and developed in PGMEA.

FIG. 15C is a scanning electron micrograph of a negative-tone patternedcoating with 18 nm wide lines on a 36 nm pitch and a LWR of 2.68 nm in acoating material formed with monobutyltin oxide hydrate followingirradiation with a 30 kV electron beam at a dose of 1191 μC/cm² of aresist film that was deposited from a freshly prepared precursorsolution and aged 39 days at room-temperature as a coated film thenexposed and developed in PGMEA.

FIG. 16 is a scanning electron micrograph of a negative-tone patternedcoating with lines on a 100 nm pitch in a coating formed with adivinyltin hydroxide/oxide coating material following irradiation with a30 kV electron beam at a dose of 75 μC/cm² and developed in PGMEA.

FIG. 17 is a plot of relative vinyl (C—H stretch) absorbance versus doseas calculated from FTIR transmission spectra of a coating formed withdivinyltin hydroxide/oxide coating materials exposed with a 30 kVelectron beam.

FIG. 18 is a scanning electron micrograph of a negative-tone patternedcoating with lines on a 32 nm pitch in a coating formed with adibutyltin oxo-carboxylate coating material following irradiation with a30 kV electron beam at a dose of 1500 μC/cm² and developed in PGMEA.

FIG. 19 is a comparative transmission-mode FTIR transmission spectra ofa dibutyltin oxo-carboxylate film in an unexposed state and afterexposure with a 30 kV electron beam at a dose of 800 μC/cm².

DETAILED DESCRIPTION OF THE INVENTION

Desirable organometallic precursor solutions, generally with non-aqueoussolvents, with a ligand structure that provides for high resolutionpatterning in which the solutions have a high degree of stability forthe formation of radiation patternable coatings with good radiationsensitivity. Desirable ligands for forming metal oxo/hydroxo complexescan comprise M-C bonds or M-O₂C bonds, where M is a selected metal atom,with particularly desirable results obtainable where M is tin, indium,antimony or a combination thereof. Desirable features of coatings formedwith the organometallic precursor solutions provide for superior directpatterning for the formation of a patterned metal oxide coating. Inembodiments of particular interest, exposure to radiation converts theirradiated coating material into a material that is resistant to removalwith a developer composition, or exposure sufficiently changes thepolarity of the coating material such that it can be selectivelyremoved. Thus, in some embodiments, the coating can be either negativelypatterned or positively patterned with the same coating. Selectiveremoval of at least a portion of the coating material can leave apattern where regions of coating have been removed to expose theunderlying substrate. After development of the coating followingirradiation, the patterned oxide materials can be used for facilitatingprocessing in device formation with excellent pattern resolution. Thecoating materials can be designed to be sensitive to selected radiation,such as extreme ultraviolet light, ultraviolet light and/or electronbeams. Furthermore, the precursor solutions can be formulated to bestable with an appropriate shelf life for commercial distribution.

To simplify the discussion herein, the metal ions with an M-C ligandbond and/or a M-O₂C ligand bonds can be referred to as organo-stabilizedmetal ions. The metal ions generally also are further bound to one ormore oxo-ligands, i.e., M-O and/or hydroxo-ligands, i.e., M-O—H, inaddition to the organic ligands. The organo-stabilizing ligands and theoxo/hydroxo ligands provide desirable features to precursor solution andcorresponding coating by providing significant control over thecondensation process to a metal oxide with resulting significantprocessing advantages. The use of organic solvents supports thestability of the solution, while surprisingly the non-aqueous solutionbased processing maintains the ability to selectively develop theresulting coating following the formation of a latent image withexcellent development rate contrast, for both positive tone patterningand negative tone patterning. Desirable precursor solutions withdissolved organo-stabilized metal ions provide for convenient solutionbased deposition to form a coating that can have high radiationsensitivity and excellent contrast with respect to etch resistance toallow for fine structure formation. The design of the precursorcomposition can provide for the formation of a coating composition witha high sensitivity to a particular radiation type and/orenergy/wavelength.

The radiation sensitive coating material can be used as either apositive radiation patterning coating or a negative radiation patterningcoating. In the negative patterning, exposure to radiation converts theirradiated coating material into a material that is more resistant toremoval with a developer composition relative to the non-irradiatedcoating material. In the positive patterning, exposure sufficientlychanges the polarity of the exposed coating material, e.g., increasingthe polarity, such that the exposed coating material can be selectivelyremoved with an aqueous solvent or other highly polar solvent.Selectively removal of at least a portion of the coating material leavesa pattern where regions have been removed to expose the underlyingsubstrate.

The formation of integrated electronic devices and the like generallyinvolves the patterning of the materials to form individual elements orcomponents within the structures. This patterning can involve differentcompositions covering selected portions of stacked layers that interfacewith each other vertically and/or horizontally to induce desiredfunctionality. The various materials can comprise semiconductors, whichcan have selected dopants, dielectrics, electrical conductors and/orother types of materials. To form high resolution patterns, radiationsensitive organic compositions can be used to introduce patterns, andthe compositions can be referred to as resists since portions of thecomposition are processed to be resistant to development/etching suchthat selective material removal can be used to introduce a selectedpattern. Radiation with the selected pattern or the negative of thepattern can be used to expose the resist and to form a pattern or latentimage with developer resistant regions and developer dissolvableregions. The radiation sensitive organometallic compositions describedherein can be used for the direct formation of desired inorganicmaterial structures within the device and/or as a radiation patternableinorganic resist that is a replacement for an organic resist. In eithercase, significant processing improvements can be exploited, and thestructure of the patterned material can be also improved.

Specifically, the precursor solution can comprise sufficient radiationsensitive organic ligands such that the solution has a molarconcentration ratio of radiation sensitive ligands to metal cations fromabout 0.1 to about 3. The coating formed from the precursor solution isinfluenced by the ligand structure of the ions in the precursor solutionand may be an equivalent ligand structure around the metal upon dryingor the ligand structure can be altered during the coating and/or dryingprocess. In particular, the organic ligand concentrations provide for asurprisingly large improvement in the precursor stability and control innetwork formation with solutions formed with organic solvents, generallypolar organic solvents. While not wanting to be limited by theory, theincrease in the radiation sensitive ligand concentration evidentlyreduces agglomeration of the metal cations, with correspondingoxo-ligands and/or hydroxo-ligands, to stabilize the solution. Thus, theprecursor solution can be stable relative to settling of solids withoutfurther stirring for at least one week and possibly for significantlylonger periods of time, such as greater than a month. Due to the longstability times, the improved precursors have increased versatility withrespect to potential commercial uses. The overall molar concentrationcan be selected to achieve a desired coating thickness and desiredcoating properties, which can be obtained consistent with desiredstability levels. Ligands with metal-carbon or metal-carboxylate bondsprovide desirable radiation sensitive ligands, and specific ligandsinclude, for example, alkyl groups (e.g., methyl, ethyl, propyl, butyl,t-butyl), aryl groups (e.g., phenyl, benzyl), alkenyl groups (e.g.,vinyl, allyl), carboxylate (e.g., acetate, propanoate, butanoate,benzoate) groups, or combinations thereof.

The polyatomic metal oxo/hydroxo cations with organic ligands can beselected to achieve the desired radiation absorption. In particular,indium and tin based coating materials exhibit good absorption of farultraviolet light at a 193 nm wavelength and extreme ultraviolet lightat a 13.5 nm wavelength. Table 1 lists optical constants (n=index ofrefraction and k=extinction coefficient) at selected wavelengths for acoating material formed from monobutyltin oxide hydrate and baked at100° C.

TABLE 1 Wavelength (nm) n k 193 1.75 0.211 248 1.79 0.0389 365 1.63 0405 1.62 0 436 1.61 0

Some precursor solutions effectively incorporate a blend of additionalmetals to provide for desirable overall properties of the coatingmaterials. The precursor solutions can comprise additional metal cationsto increase the absorption of some radiation wavelengths of significancefor lithography. The metal ion concentration can be selected to providedesired properties for the precursor solution, with more dilutesolutions generally consistent with the formation of thinner coatingmaterials, although coating properties also depend on the depositiontechnique.

The ligand structure of the precursor compositions are believed toprovide the desirable stability of the precursor solutions as well asthe radiation patterning function. In particular, it is believed thatthe absorption of radiation can provide for the disruption of the bondsbetween the metal and the organic ligands to create a differentiation ofthe composition at the irradiated and non-irradiated sections of thecoated material. Thus, the compositional changes to form the improvedprecursor solutions also provide for improved development of the image.In particular, the irradiated coating material may result in a stableinorganic metal oxide material with a tunable response to the developer,e.g., through proper developer selection either positive ornegative-tone images can be developed. In some embodiments, suitabledevelopers include, for example, 2.38% TMAH, i.e., the semiconductorindustry standard. The coating layers can be made thin without patternloss during development from removing the coating material from regionswhere the coating material is intended to remain following development.Compared to conventional organic resists, the materials described hereinhave extremely high resistance to many etch chemistries for commerciallyrelevant functional layers. This enables process simplification throughavoidance of intermediate sacrificial inorganic pattern transfer layersthat would otherwise be used to supplement the patterned organic resistswith respect to the mask function. Also, the coating material canprovide for convenient double patterning. Specifically, following athermal treatment, patterned portions of the coating material are stablewith respect to contact with many compositions including furtherprecursor solutions. Thus, multiple patterning can be performed withoutremoving previously deposited hard-mask or resist coating materials.

The patterned coating material can be subsequently removed after thepatterned material is used as a mask to pattern desired functionalmaterials. Alternatively, the resulting patterned material can beincorporated into the structure following appropriate stabilizationthrough at least some condensation into an inorganic metal oxidematerial, as a component of ultimate device(s). If the patternedinorganic coating material is incorporated into the structure, forexample as a stable dielectric layer, many steps of the processingprocedure can be eliminated through the use of a direct patterning ofthe material with radiation. Alternatively, it has been found that veryhigh resolution structures can be formed using thin inorganic coatingmaterials exposed using short wavelength electromagnetic radiationand/or electron beams, and that line-width roughness can be reduced tovery low levels for the formation of improved patterned structures.

The precursor solution comprises polynuclear metal oxo/hydroxo cationsand organic ligands. Polynuclear metal oxo/hydroxo cations, alsodescribed as metal suboxide cations, are polyatomic cations with a metalelement and covalently bonded oxygen atoms. Metal suboxide cations withperoxide based ligands are described in U.S. Pat. No. 8,415,000 toStowers et al. (the '000 patent), entitled “Patterned Inorganic Layers,Radiation Based Patterning Compositions and Corresponding Methods,”incorporated herein by reference. Aqueous solutions of metal suboxidesor metal hydroxides can tend to be unstable with respect to gellingand/or precipitation. In particular, the solutions are unstable uponsolvent removal and can form oxo-hydroxide networks with the metalcations. Incorporation of a radiation-sensitive ligand such as peroxideinto such a solution can improve stability, but the backgroundinstability associated with network formation may persist. Thisuncontrolled network formation effectively decreases the radiationsensitivity and/or development rate contrast of the coated material byproviding a development rate determining pathway independent ofirradiation.

The new precursor solutions have been formulated with improved stabilityand control of network formation and precipitation relative to inorganicresist materials with peroxide based ligands. Characterization ofligands as radiation sensitive in this case refers to the lability ofthe metal-ligand bond following absorption of radiation, so thatradiation can be used to induce a chemical change in the material. Inparticular, organic ligands stabilize the precursor solutions while alsoproviding control over the processing of the materials, and selection ofthe ratio of organic ligands to metal ions can be adjusted to controlproperties of the solution and the resulting coatings. In particular, ifthe mole ratio of organic ligands to the metal cations is between about0.1 and about 3, more stable solutions generally can be formed. The morestable precursor solutions provide an added advantage of greatercontrast between the ultimate irradiated coating material andun-irradiated coating material since the rupture of the organic ligandbonds with the metal can be accomplished with radiation to improvedevelopment rate contrast in the coating material with the latent image.

Refined precursor solutions with greater stability also provide for acoating material having the potential of a greater development ratecontrast between the radiation exposed and unexposed portions of thesubstrate, which surprisingly can be achieved simultaneously with eitherpositive tone patterning or negative tone patterning. Specifically, theirradiated coating material or the un-irradiated coating material can berelatively more easily dissolved by suitable developer compositions.Thus, with the improved compositions and corresponding materials,positive- or negative-tone imaging can be achieved through choice ofdeveloper. At the same time, the pitch can be made very small betweenadjacent elements with appropriate isolation, generally electricalisolation, between the adjacent elements. The irradiated coatingcomposition can be very sensitive to a subsequent development/etchingprocess so that the coating composition can be made very thin withoutcompromising the efficacy of the development process with respect toselective and clean removal of the coating composition while leavingappropriate portions of the irradiated patterning composition on thesurface of the substrate. The ability to shorten the exposure time tothe developer further is consistent with the use of thin coatingswithout damaging the patterned portions of the coating.

The precursor solutions can be deposited generally with any reasonablecoating or printing technique as described further below. The coatinggenerally is dried, and heat can be applied to stabilize the coatingprior to irradiation. Generally, the coatings are thin, such as with anaverage thickness of less than 10 microns, and very thin submicroncoatings can be desirable to pattern very small features. The driedcoating can be subjected to appropriate radiation, e.g., extremeultraviolet light, e-beam or ultraviolet light, to form a latent imagein the coating. The latent image is contacted with the developer to forma physical image, i.e. a patterned coating. The patterned coating can befurther heated to stabilize the remaining coating patterned on thesurface. The patterned coating can be used as a physical mask to performfurther processing, e.g., etching of the substrate and/or deposition ofadditional materials according to the pattern. At appropriate points ofthe processing, the remaining patterned coating can be removed, althoughthe patterned coating can be incorporated into the ultimate structure.Very fine features can be accomplished effectively with the patterningcompositions described herein.

Precursor Solutions

The precursor solutions for forming the resist coatings generallycomprise metal cations with appropriate organic-stabilizing ligands inan organic solvent, generally an organic solvent. The precursorsolutions and the ultimate resist coatings are based on metal oxidechemistry, and the organic solutions of metal polycations with organicligands provide stable solutions with good resist properties. Theligands provide the radiation sensitivity, and the particular selectionof ligands can influence the radiation sensitivity. In particular, theprecursor solutions can be designed to achieve desired levels ofradiation absorption for a selected radiation based on the selection ofthe metal cations as well as the associated ligands. The concentrationof ligand stabilized metal cations in the solution can be selected toprovide suitable solution properties for a particular depositionapproach, such as spin coating. Metals of particular effectiveness withrespect to stability and processing effectiveness are group 13, 14 and15 metals. To correspondingly provide a high absorption of radiationgenerally used for patterning, it is desirable to include Sn, In and Sbmetals in the precursor solutions, although these metals can be combinedwith other metals to adjust the properties, especially the radiationabsorption. The precursor solutions have been formulated to achieve veryhigh levels of stability such that the precursor solutions haveappropriate shelf lives for commercial products. As described in thefollowing section, the precursor solutions can be applied to a substratesurface, dried and further processed to form an effective radiationresist. The precursor solutions are designed to form a coatingcomposition upon at least partial solvent removal and ultimately aninorganic solid dominated by metal oxides upon irradiation and/orthermal treatment, exposure to a plasma, or similar processing.

The precursor solutions generally comprise one or more metal cations. Inaqueous solutions, metal cations are hydrated due to interactions withthe water molecules, and hydrolysis can take place to bond oxygen atomsto the metal ion to form hydroxide ligands or oxo bonds with thecorresponding release of hydrogen ions. The nature of the interactionsis generally pH dependent. As additional hydrolysis takes place inaqueous solutions, the solutions can become unstable with respect toprecipitation of the metal oxide or with respect to gelation.Ultimately, it is desirable to form the oxide material, but thisprogression can be controlled better with the precursor solutions basedon organic solvents with organic ligand stabilized metal cations. Withthe precursor solutions based on organic-stabilization ligands and anorganic solvent, progression to the oxide can be controlled as part ofthe procedure for processing the solution first to a coating materialand then to the ultimate metal oxide composition with organic ligands.As described herein, organic ligands can be used to provide significantcontrol to the processing of the solution to an effective radiationresist composition.

Thus, the solutions of the metal cations are poised for furtherprocessing. In particular, it can be desirous to use as an addedcomponent of the precursor solution, a polynuclear metal oxo/hydroxocation that can poise the solution further toward a metal oxidecomposition. In general, the precursor solution comprises from about0.01M to about 1.4M metal polynuclear oxo/hydroxo cation, in furtherembodiments from about 0.05M to about 1.2M, and in additionalembodiments from about 0.1M to about 1.0M. A person of ordinary skill inthe art will recognize that additional ranges of metal polynuclearoxo/hydroxo cations within the explicit ranges above are contemplatedand are within the present disclosure.

Tin, antimony and/or indium are particularly suitable metals forformation of polynuclear metal oxo/hydroxo cations for the precursorsolutions described herein. In particular, tin has a desirable chemistrybased on organic ligands. Additional metals can be provided to producemore complex polynuclear metal oxo/hydroxo cation formulations,including, for example, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As,Y, La, Ce, Lu or combinations thereof. The additional metals can be asalternatives to or in addition to tin ions, antimony ions and/or indiumions (tin/antimony/indium ions). If blends of metal ions are used, insome embodiments the mole ratio of tin/antimony/indium with additionalmetal ion(s) can be up to about 1 non-tin/antimony/indium metal ion pereach tin/antimony/indium ion and in further embodiments from about 0.1to about 0.75 non-tin/indium metal ion per tin/antimony/indium metalion. If blends of metal ions are used, the metal ions may be in complexmultiple metal oxo-hydroxo clusters in solution or in distinct metaloxo-hydroxo clusters. The precise cluster form in solution may or maynot be known, and the resulting coating generally can provide desiredfunction whether or not the cluster structure in solution is known. Asnoted above, the state of the cations in solution is pH dependent, suchthat the initial state of oxygen coordination can change in solution,but the trend is toward hydrolysis and condensation leading to oxideformation. It has been found that organic ligands can hinder theformation of a metal-oxygen network that leads to gelation andultimately precipitation. Thus, the organic ligand can be used to form astable state that is poised for transformation to oxide throughselective radiation exposures. The use of organic ligands also extendsthe choices of precursor solvents and developer to include bothwater-based and organic solvents.

The metal generally significantly influences the absorption ofradiation. Therefore, the metal cations can be selected based on thedesired radiation and absorption cross section. Indium and tin providestrong absorption of extreme ultraviolet light at 13.5 nm. Incombination with organic ligands they also provide good absorption ofultraviolet light at 193 nm wavelength. Hf also provides good absorptionof electron beam material and extreme UV radiation. Further tuning ofthe composition for radiation absorption can be adjusted based on theaddition of other metal ions. For example, one or more metalcompositions comprising Ti, V, Mo, or W or combinations thereof can beadded to the precursor solution to form a coating material with anabsorption edge moved to longer wavelengths, to provide, for example,sensitivity to 248 nm wavelength ultraviolet light. The energy absorbedis modulated by the metal-organic interactions, which can result in therupturing of the metal-ligand and the desired control over the materialproperties.

The organic-based ligands stabilize the composition with respect tocondensation. In particular, at high relative concentration oforganic-based ligands, formation of condensed metal oxides or metalhydroxides are very slow if the condensation spontaneously occurs at allat room temperature. Based on the discovery of this stabilizationproperty, solutions can be formed with high concentrations of radiationsensitive ligands that have good shelf stability while retainingconvenient processing to form coatings. Radiation sensitive ligandsinclude carboxylates and organic moieties forming a metal-carbon bond,e.g., tin-carbon bond. Energy from absorbed radiation can break themetal-organic ligand bond. As these bonds are broken, the correspondingstabilization with respect to condensation is reduced or lost. Thecomposition can change through formation of M-OH or through condensationto form M-O M bonds, where M represents a metal atom. Thus, chemicalchanges can be controlled with radiation. Compositions with highradiation sensitive ligand concentrations can be highly stable withrespect to the avoidance of spontaneous formation of hydroxide andcondensation. Some suitable metal compositions with desired ligandstructures can be purchased from commercial sources, such as Alfa Aesar(MA, USA) and TCI America (OR, USA), see Examples below, and othermetal-ligand compositions can be synthesized as described below.

The organic ligands can be, for example, alkyls (e.g., methyl, ethyl,propyl, butyl, t-butyl, aryl (phenyl, benzyl)), alkenyls (e.g., vinyl,allyl), and carboxylates (acetate, propanoate, butanoate benzoate). Theprecursor composition generally comprises a ligand concentration of froma factor of about 0.25 to about 4 times the metal cation concentration,in further embodiments from about 0.5 to about 3.5 in additionalembodiments from about 0.75 to about 3, and in other embodiments fromabout 1 to about 2.75 times the metal cation concentration. A person ofordinary skill in the art will recognize that additional ranges ofligand concentrations within the explicit ranges above are contemplatedand are within the present disclosure.

With respect to the oxo/hydroxo ligands for the metal ions, theseligands can be formed during processing through hydrolysis. In someembodiments, the hydrolysis can involve replacement of halide ligands ina basic aqueous solution with subsequent transfer to an organic solvent.A specific example is presented below. Basically, a compositioncomprising the metal ions with organic stabilizing ligands and halideligands are dissolved in an organic solvent, which is then contactedwith a basic aqueous solution, whereupon substitution of the halideligands with hydroxo ligands may occur. After providing enough time toform hydroxo ligands, the aqueous solution can be separated from theorganic phase assuming that the organic liquid is not soluble in theaqueous liquid. In some embodiments, the oxo/hydroxo ligands can beformed through hydrolysis from atmospheric water. The hydrolyzable metalion composition can be heated in the presence of atmospheric moisture sothat the oxo/hydroxo ligands form directly in the coating material,which can be relatively facile due to the high surface area. An exampleof hydrolysis from atmospheric water is also described below.

With respect to formation of the organo-stabilizing ligands, these canalso be formed in solution to form desired compositions. With respect tothe carboxylate ligands, the corresponding carboxylic acid or a saltthereof can be dissolved in solution with the metal cations. If desiredthe pH of the solution can be adjusted to facilitate bonding of thecarboxylate groups to the metal, and heat may be applied to furtherdrive the process. In general, the reaction can be performed in anaqueous solvent with subsequent transfer to an organic solvent ordirectly performed in an organic solvent. Also, M-C bonds can also beformed in a solution phase substitution reaction. The followingreactions are representative suitable reactions for the substitutionreactions to form Sn—C bonds, and similar reactions follow for othermetal ions:

nRCl+Sn→R_(n)SnCl_(4-n)+Residual

4 RMgBr+SnCl₄→R₄Sn+4 MgBrCl

3 SnCl₄+4R₃Al→3 R₄Sn+4 AlCl₃

R₄Sn+SnCl₄→2 R₂SnCl ₂,

Where R represents an organic ligand. Generally, different suitablehalides can be substituted in the above reactions. The reactions can becarried out in a suitable organic solvent in which the reactants havereasonable solubility.

In general, the desired compounds can be dissolved in an organicsolvent, e.g., alcohols, esters or combinations thereof. In particular,suitable solvents include, for example, aromatic compounds (e.g.,xylenes, toluene), esters (propylene glycol monomethyl ether acetate,ethyl acetate, ethyl lactate), alcohols (e.g., 4-methyl-2-pentanol,1-butanol, anisole), ketones (e.g., methyl ethyl ketone), and the like.In general, organic solvent selection can be influenced by solubilityparameters, volatility, flammability, toxicity, viscosity and potentialchemical interactions with other processing materials. After thecomponents of the solution are dissolved and combined, the character ofthe species may change as a result of partial hydration andcondensation, especially during the coating process. When thecomposition of the solution is referenced herein, the reference is tothe components as added to the solution, since complex formulations mayproduce metal polynuclear species in solution that may not be wellcharacterized. For certain applications it is desirable for the organicsolvent to have a flash point of no less than about 10° C., in furtherembodiments no less than about 20° C. and in further embodiment no lessthan about 25° C. and a vapor pressure at 20° C. of no more than about10 kPa, in some embodiments no more than about 8 kPa and in furtherembodiments no more than about 6 kPa. A person of ordinary skill in theart will recognize that additional ranges of flash point and vaporpressure within the explicit ranges above are contemplated and arewithin the present disclosure.

In general, precursor solutions are well mixed using appropriate mixingapparatuses suitable for the volume of material being formed. Suitablefiltration can be used to remove any contaminants or other componentsthat do not appropriately dissolve. In some embodiments, it may bedesirable to form separate solutions that can be combined to form theprecursor solution from the combination. Specifically, separatesolutions can be formed comprising one or more of the following: themetal polynuclear oxo/hydroxo cations, any additional metal cations, andthe organic ligands. If multiple metal cations are introduced, themultiple metal cations can be introduced into the same solution and/orin separate solutions. Generally, the separate solutions or the combinedsolutions can be well mixed. In some embodiments, the metal cationsolution is then mixed with the organic-based ligand solution such thatthe organic-based ligand can conjugate with the metal cations. Theresulting solution can be referred to as a stabilized metal cationsolution. In some embodiments, the stabilized metal cation solution isallowed to react for a suitable period of time to provide for stableligand formation, which may or may not also involve cluster formation insolution, whether or not mixed metal ions are introduced. In someembodiments, the reaction or stabilization time for the solution can befor at least about five minutes, in other embodiments at least about 1hour, and in further embodiments from about 2 hours to about 48 hoursprior to further processing. A person of ordinary skill in the art willrecognize that additional ranges of stabilization periods arecontemplated and are within the present disclosure.

The concentrations of the species in the precursor solutions can beselected to achieve desired physical properties of the solution. Inparticular, lower concentrations overall can result in desirableproperties of the solution for certain coating approaches, such as spincoating, that can achieve thinner coatings using reasonable coatingparameters. It can be desirable to use thinner coatings to achieveultrafine patterning as well as to reduce material costs. In general,the concentration can be selected to be appropriate for the selectedcoating approach. Coating properties are described further below.

As noted above, a relatively large ratio of organic-based ligandrelative to the metal cations can be used to greatly stabilize theprecursor solutions. Stability of the precursor solutions can beevaluated with respect to changes relative to the initial solution.Specifically, a solution has lost stability if phase separation occurswith the production of large sol particles or if the solution loses itsability to perform desired pattern formation. Based on the improvedstabilization approaches described herein, the solutions can be stablefor at least about a week without additional mixing, in furtherembodiments at least about 2 weeks, in other embodiments at least about4 weeks. A person of ordinary skill in the art will recognize thatadditional ranges of stabilization times are contemplated and are withinthe present disclosure. The solutions can be formulated with sufficientstabilization times that the solutions can be commercially distributedwith appropriate shelf lives.

Coating Material

A coating material is formed through the deposition and subsequentprocessing of the precursor solution onto a selected substrate. Asubstrate generally presents a surface onto which the coating materialcan be deposited, and the substrate may comprise a plurality of layersin which the surface relates to an upper most layer. In someembodiments, the substrate surface can be treated to prepare the surfacefor adhesion of the coating material. Also, the surface can be cleanedand/or smoothed as appropriate. Suitable substrate surfaces can compriseany reasonable material.

Some substrates of particular interest include, for example, siliconwafers, silica substrates, other inorganic materials, polymersubstrates, such as organic polymers, composites thereof andcombinations thereof across a surface and/or in layers of the substrate.Wafers, such as relatively thin cylindrical structures, can beconvenient, although any reasonable shaped structure can be used.Polymer substrates or substrates with polymer layers on non-polymerstructures can be desirable for certain applications based on their lowcost and flexibility, and suitable polymers can be selected based on therelatively low processing temperatures that can be used for theprocessing of the patternable materials described herein. Suitablepolymers can include, for example, polycarbonates, polyimides,polyesters, polyalkenes, copolymers thereof and mixtures thereof. Ingeneral, it is desirable for the substrate to have a flat surface,especially for high resolution applications.

In general, any suitable coating process can be used to deliver theprecursor solution to a substrate. Suitable coating approaches caninclude, for example, spin coating, spray coating, dip coating, knifeedge coating, printing approaches, such as inkjet printing and screenprinting, and the like. Some of these coating approaches form patternsof coating material during the coating process, although the resolutionavailable currently from printing or the like has a significantly lowerlevel of resolution than available from radiation based patterning asdescribed herein. The coating material can be applied in multiplecoating steps to provide greater control over the coating process. Forexample, multiple spin coatings can be performed to yield an ultimatecoating thickness desired. The heat processing described below can beapplied after each coating step or after a plurality of coating steps.

If patterning is performed using radiation, spin coating can be adesirable approach to cover the substrate relatively uniformly, althoughthere can be edge effects. In some embodiments, a wafer can be spun atrates from about 500 rpm to about 10,000 rpm, in further embodimentsfrom about 1000 rpm to about 7500 rpm and in additional embodiments fromabout 2000 rpm to about 6000 rpm. The spinning speed can be adjusted toobtain a desired coating thickness. The spin coating can be performedfor times from about 5 seconds to about 5 minutes and in furtherembodiments from about 15 seconds to about 2 minutes. An initial lowspeed spin, e.g. at 50 rpm to 250 rpm, can be used to perform an initialbulk spreading of the composition across the substrate. A back siderinse, edge bead removal step or the like can be performed with water orother suitable solvent to remove any edge bead. A person or ordinaryskill in the art will recognize that additional ranges of spin coatingparameters within the explicit ranges above are contemplated and arewithin the present disclosure.

The thickness of the coating generally can be a function of theprecursor solution concentration, viscosity and the spin speed for spincoating. For other coating processes, the thickness can generally alsobe adjusted through the selection of the coating parameters. In someembodiments, it can be desirable to use a thin coating to facilitateformation of small and highly resolved features in the subsequentpatterning process. For example, the coating materials after drying canhave an average thickness of no more than about 10 microns, in otherembodiments no more than about 1 micron, in further embodiments no morethan about 250 nanometers (nm), in additional embodiments from about 1nanometers (nm) to about 50 nm, in other embodiments from about 2 nm toabout 40 nm and in some embodiments from about 3 nm to about 25 nm. Aperson of ordinary skill in the art will recognize that additionalranges of thicknesses within the explicit ranges above are contemplatedand are within the present disclosure. The thickness can be evaluatedusing non-contact methods of x-ray reflectivity and/or ellipsometrybased on the optical properties of the film. In general, the coatingsare relatively uniform to facilitate processing. In some embodiments,the variation in thickness of the coating varies by no more than ±50%from the average coating thickness, in further embodiments no more than±40% and in additional embodiments no more than about 25% relative tothe average coating thickness. In some embodiments, such as highuniformity coatings on larger substrates, the evaluation of coatinguniformity may be evaluated with a 1 centimeter edge exclusion, i.e.,the coating uniformity is not evaluated for portions of the coatingwithin 1 centimeter of the edge. A person of ordinary skill in the artwill recognize that additional ranges within the explicit ranges aboveare contemplated and are within the present disclosure.

The coating process itself can result in the evaporation of a portion ofthe solvent since many coating processes form droplets or other forms ofthe coating material with larger surface areas and/or movement of thesolution that stimulates evaporation. The loss of solvent tends toincrease the viscosity of the coating material as the concentration ofthe species in the material increases. An objective during the coatingprocess can be to remove sufficient solvent to stabilize the coatingmaterial for further processing. In general, the coating material can beheated prior to radiation exposure to further drive off solvent andpromote densification of the coating material. The dried coatingmaterial may generally form a polymeric metal oxo/hydroxo network basedon the oxo-hydroxo ligands to the metals in which the metals also havesome organic ligands, or a molecular solid comprised of polynuclearmetal oxo/hydroxo species with organic ligands.

The solvent removal process may or may not be quantitatively controlledwith respect to specific amounts of solvent remaining in the coatingmaterial, and empirical evaluation of the resulting coating materialproperties generally can be performed to select processing conditionsthat are effective for the patterning process. While heating is notneeded for successful application of the process, it can be desirable toheat the coated substrate to speed the processing and/or to increase thereproducibility of the process. In embodiments in which heat is appliedto remove solvent, the coating material can be heated to temperaturesfrom about 45° C. to about 250° C. and in further embodiments from about55° C. to about 225° C. The heating for solvent removal can generally beperformed for at least about 0.1 minute, in further embodiments fromabout 0.5 minutes to about 30 minutes and in additional embodiments fromabout 0.75 minutes to about 10 minutes. A person of ordinary skill inthe art will recognize that additional ranges of heating temperature andtimes within the explicit ranges above are contemplated and are withinthe present disclosure. As a result of the heat treatment anddensification of the coating material, the coating material can exhibitan increase in index of refraction and in absorption of radiationwithout significant loss of contrast.

Patterned Exposure and Patterned Coating Material

The coating material can be finely patterned using radiation. As notedabove, the composition of the precursor solution and thereby thecorresponding coating material can be designed for sufficient absorptionof a desired form of radiation. The absorption of the radiation resultsin energy that can break the bonds between the metal and organic ligandsso that at least some of the organic-based ligands are no longeravailable to stabilize the material. With the absorption of a sufficientamount of radiation, the exposed coating material condenses, i.e. formsan enhanced metal oxo/hydroxo network, which may involve water absorbedfrom the ambient atmosphere. The radiation generally can be deliveredaccording to a selected pattern. The radiation pattern is transferred toa corresponding pattern or latent image in the coating material withirradiated areas and un-irradiated areas. The irradiated areas comprisechemically altered coating material, and the un-irradiated areascomprise generally the as-formed coating material. As noted below, verysharp edges can be formed upon development of the coating material withthe removal of the un-irradiated coating material or alternatively withselective removal of the irradiated coating material.

Radiation generally can be directed to the coated substrate through amask or a radiation beam can be controllably scanned across thesubstrate. In general, the radiation can comprise electromagneticradiation, an electron beam (beta radiation), or other suitableradiation. In general, electromagnetic radiation can have a desiredwavelength or range of wavelengths, such as visible radiation,ultraviolet radiation or x-ray radiation. The resolution achievable forthe radiation pattern is generally dependent on the radiationwavelength, and a higher resolution pattern generally can be achievedwith shorter wavelength radiation. Thus, it can be desirable to useultraviolet light, x-ray radiation or an electron beam to achieveparticularly high resolution patterns. Following International StandardISO 21348 (2007) incorporated herein by reference, ultraviolet lightextends between wavelengths of greater than or equal 100 nm and lessthan 400 nm. A krypton fluoride laser can be used as a source for 248 nmultraviolet light. The ultraviolet range can be subdivided in severalways under accepted Standards, such as extreme ultraviolet (EUV) fromgreater than or equal 10 nm to less than 121 nm and far ultraviolet(FUV) from greater than or equal to 122 nm to less than 200 nm A 193 nmline from an argon fluoride laser can be used as a radiation source inthe FUV. EUV light has been used for lithography at 13.5 nm, and thislight is generated from a Xe or Sn plasma source excited using highenergy lasers or discharge pulses. Soft x-rays can be defined fromgreater than or equal 0.1 nm to less than 10 nm.

The amount of electromagnetic radiation can be characterized by afluence or dose which is obtained by the integrated radiative flux overthe exposure time. Suitable radiation fluences can be from about 1mJ/cm² to about 150 mJ/cm², in further embodiments from about 2 mJ/cm²to about 100 mJ/cm², and in further embodiments from about 3 mJ/cm² toabout 50 mJ/cm². A person of ordinary skill in the art will recognizethat additional ranges of radiation fluences within the explicit rangesabove are contemplated and are within the present disclosure.

With electron beam lithography, the electron beam generally inducessecondary electrons which generally modify the irradiated material. Theresolution can be a function at least in part of the range of thesecondary electrons in the material in which a higher resolution isgenerally believed to result from a shorter range of the secondaryelectrons. Based on high resolution achievable with electron lithographyusing the inorganic coating materials described herein, the range of thesecondary electrons in the inorganic material is limited. Electron beamscan be characterized by the energy of the beam, and suitable energiescan range from about 5 V to about 200 kV (kilovolt) and in furtherembodiments from about 7.5 V to about 100 kV. Proximity-corrected beamdoses at 30 kV can range from about 0.1 microcoulombs per centimetersquared to about 5 millicoulombs per centimeter squared (mC/cm²), infurther embodiments from about 0.5 μC/cm² to about 1 mC/cm² and in otherembodiments from about 1 μC/cm² to about 100 μC/cm². A person ofordinary skill in the art can compute corresponding doses at other beamenergies based on the teachings herein and will recognize thatadditional ranges of electron beam properties within the explicit rangesabove are contemplated and are within the present disclosure.

Based on the design of the coating material, there is a large contrastof material properties between the irradiated regions that havecondensed coating material and the un-irradiated, coating material withsubstantially intact organic ligands. It has been found that thecontrast can be improved with a post-irradiation heat treatment,although satisfactory results can be achieved in some embodimentswithout post-irradiation heat treatment. The post-exposure heattreatment seems to anneal the irradiated coating material to increaseits condensation without significantly condensing the un-irradiatedregions of coating material based on thermal breaking of the organicligand-metal bonds. For embodiments in which a post irradiation heattreatment is used, the post-irradiation heat treatment can be performedat temperatures from about 45° C. to about 250° C., in additionalembodiments from about 50° C. to about 190° C. and in furtherembodiments from about 60° C. to about 175° C. The post exposure heatingcan generally be performed for at least about 0.1 minute, in furtherembodiments from about 0.5 minutes to about 30 minutes and in additionalembodiments from about 0.75 minutes to about 10 minutes. A person ofordinary skill in the art will recognize that additional ranges ofpost-irradiation heating temperature and times within the explicitranges above are contemplated and are within the present disclosure.This high contrast in material properties further facilitates theformation of sharp lines in the pattern following development asdescribed in the following section.

Following exposure with radiation, the coating material is patternedwith irradiated regions and un-irradiated regions. Referring to FIGS. 1and 2 , a patterned structure 100 is shown comprising a substrate 102, athin film 103 and patterned coating material 104. Patterned coatingmaterial 104 comprises regions 110, 112, 114, 116 of irradiated coatingmaterial and uncondensed regions 118, 120 of un-irradiated coatingmaterial. The patterned formed by condensed regions 110, 112, 114, 116and uncondensed regions 118, 120, 122 represent a latent image in to thecoating material, and the development of the latent image is discussedin the following section.

Development and Patterned Structure

Development of the image involves the contact of the patterned coatingmaterial including the latent image to a developer composition to removeeither the un-irradiated coating material to form the negative image orthe irradiated coating to form the positive image. Using the resistmaterials described herein, effective negative patterning or positivepatterning can be performed with desirable resolution using appropriatedeveloping solutions, generally based on the same coating. Inparticular, the irradiated regions are at least partially condensed toincrease the metal oxide character so that the irradiated material isresistant to dissolving by organic solvents while the un-irradiatedcompositions remain soluble in the organic solvents. Reference to acondensed coating material refers to at least partial condensation inthe sense of increasing the oxide character of the material relative toan initial material. On the other hand, the un-irradiated material isnot soluble in weak aqueous bases or acids due to the hydrophobicnatural of the material so that aqueous bases can be used to remove theirradiated material while maintaining the non-irradiated material forpositive patterning.

The coating compositions with organic-stabilization ligands produce amaterial that is inherently relatively hydrophobic. Irradiation to breakat least some of the organic metal bonds converts the material into aless hydrophobic, i.e., more hydrophilic, material. This change incharacter provides for a significant contrast between the irradiatedcoating and non-irradiated coating that provides for the ability to doboth positive tone patterning and negative tone patterning with the sameresist composition. Specifically, the irradiated coating materialcondenses to some degree into a more of a metal oxide composition;however, the degree of condensation generally is moderate withoutsignificant heating so that the irradiated material is relativelystraightforward to develop with convenient developing agents. Incontrast, inorganic resist materials based on metal oxo-hydroxochemistry with peroxide stabilization ligands, as described in the '000patent cited above, are inherently more hydrophilic prior toirradiation, and the irradiated peroxide-based coatings can be condensedto a more significant degree by irradiation so that the un-irradiatedresist can be removed with weak acids or bases while the irradiatedperoxide-based coatings can be developed similar to a metal oxidematerial.

With respect to negative tone imaging, referring to FIGS. 3 and 4 , thelatent image of the structure shown in FIGS. 1 and 2 has been developedthrough contact with a developer to form patterned structure 130. Afterdevelopment of the image, substrate 102 is exposed along the top surfacethrough openings 132, 134. Openings 132, 134 are located at thepositions of uncondensed regions 118, 120, respectively. With respect topositive tone imaging, referring to FIGS. 5 and 6 , the latent image ofthe structure shown in FIGS. 1 and 2 has been developed to formpatterned structure 140. Patterned structure 140 has the conjugate imageof patterned structure 130. Patterned structure 140 has substrate 102exposed at positions of irradiated regions 110, 112, 114, 116 that aredeveloped to form openings 142, 144, 146, 148.

For the negative tone imaging, the developer can be an organic solvent,such as the solvents used to form the precursor solutions. In general,developer selection can be influenced by solubility parameters withrespect to the coating material, both irradiated and non-irradiated, aswell as developer volatility, flammability, toxicity, viscosity andpotential chemical interactions with other process material. Inparticular, suitable developers include, for example, aromatic compounds(e.g., benzene, xylenes, toluene), esters (e.g., propylene glycolmonomethyl ester acetate, ethyl acetate, ethyl lactate, n-butyl acetate,butyrolactone), alcohols (e.g., 4-methyl-2-pentanol, 1-butanol,isopropanol, anisole), ketones (e.g., methyl ethyl ketone, acetone,cyclohexanone), ethers (e.g., tetrahydrofuran, dioxane) and the like.The development can be performed for about 5 seconds to about 30minutes, in further embodiments from about 8 seconds to about 15 minutesand in addition embodiments from about 10 seconds to about 10 minutes. Aperson of ordinary skill in the art will recognize that additionalranges within the explicit ranges above are contemplated and are withinthe present disclosure.

For positive tone imaging, the developer generally can be aqueous acidsor bases. In some embodiments, aqueous bases can be used to obtainsharper images. To reduce contamination from the developer, it can bedesirable to use a developer that does not have metal atoms. Thus,quaternary ammonium hydroxide compositions, such as tetraethylammoniumhydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxideor combinations thereof, are desirable as developers. In general, thequaternary ammonium hydroxides of particular interest can be representedwith the formula R₄NOH, where R=a methyl group, an ethyl group, a propylgroup, a butyl group, or combinations thereof. The coating materialsdescribed herein generally can be developed with the same developercommonly used presently for polymer resists, specifically tetramethylammonium hydroxide (TMAH). Commercial TMAH is available at 2.38 weightpercent, and this concentration can be used for the processing describedherein. Furthermore, mixed quaternary tetraalkyl-ammonium hydroxides canbe used. In general, the developer can comprise from about 0.5 to about30 weight percent, in further embodiments from about 1 to about 25weight percent and in other embodiments from about 1.25 to about 20weight percent tetra-alkylammonium hydroxide or similar quaternaryammonium hydroxides. A person of ordinary skill in the art willrecognize that additional ranges of developer concentrations within theexplicit ranges above are contemplated and are within the presentdisclosure.

In addition to the primary developer composition, the developer cancomprise additional compositions to facilitate the development process.Suitable additives include, for example, dissolved salts with cationsselected from the group consisting of ammonium, d-block metal cations(hafnium, zirconium, lanthanum, or the like), f-block metal cations(cerium, lutetium or the like), p-block metal cations (aluminum, tin, orthe like), alkali metals (lithium, sodium, potassium or the like), andcombinations thereof, and with anions selected from the group consistingof fluoride, chloride, bromide, iodide, nitrate, sulfate, phosphate,silicate, borate, peroxide, butoxide, formate,ethylenediamine-tetraacetic acid (EDTA), tungstate, molybdate, or thelike and combinations thereof. Other potentially useful additivesinclude, for example, molecular chelating agents, such as polyamines,alcohol amines, amino acids or combinations thereof. If the optionaladditives are present, the developer can comprise no more than about 10weight percent additive and in further embodiments no more than about 5weight percent additive. A person of ordinary skill in the art willrecognize that additional ranges of additive concentrations within theexplicit ranges above are contemplated and are within the presentdisclosure. The additives can be selected to improve contrast,sensitivity and line width roughness. The additives in the developer canalso inhibit formation and precipitation of metal oxide particles.

With a weaker developer, e.g., lower concentration aqueous developer,diluted organic developer or compositions in which the coating has alower development rate, a higher temperature development process can beused to increase the rate of the process. With a stronger developer, thetemperature of the development process can be lower to reduce the rateand/or control the kinetics of the development. In general, thetemperature of the development can be adjusted between the appropriatevalues consistent with the volatility of the solvents. Additionally,developer with dissolved coating material near the developer-coatinginterface can be dispersed with ultrasonication during development.

The developer can be applied to the patterned coating material using anyreasonable approach. For example, the developer can be sprayed onto thepatterned coating material. Also, spin coating can be used. Forautomated processing, a puddle method can be used involving the pouringof the developer onto the coating material in a stationary format. Ifdesired spin rinsing and/or drying can be used to complete thedevelopment process. Suitable rinsing solutions include, for example,ultrapure water, methyl alcohol, ethyl alcohol, propyl alcohol andcombinations thereof for negative patterning and ultrapure water forpositive patterning. After the image is developed, the coating materialis disposed on the substrate as a pattern.

After completion of the development step, the coating materials can beheat treated to further condense the material and to further dehydratethe material. This heat treatment can be particularly desirable forembodiments in which the oxide coating material is incorporated into theultimate device, although it may be desirable to perform the heattreatment for some embodiments in which the coating material is used asa resist and ultimately removed if the stabilization of the coatingmaterial is desirable to facilitate further patterning. In particular,the bake of the patterned coating material can be performed underconditions in which the patterned coating material exhibits desiredlevels of etch selectivity. In some embodiments, the patterned coatingmaterial can be heated to a temperature from about 100° C. to about 600°C., in further embodiments from about 175° C. to about 500° C. and inadditional embodiments from about 200° C. to about 400° C. The heatingcan be performed for at least about 1 minute, in other embodiment forabout 2 minutes to about 1 hour, in further embodiments from about 2.5minutes to about 25 minutes. The heating may be performed in air,vacuum, or an inert gas ambient, such as Ar or N₂. A person of ordinaryskill in the art will recognize that additional ranges of temperaturesand time for the heat treatment within the explicit ranges above arecontemplated and are within the present disclosure.

With conventional organic resists, structures are susceptible to patterncollapse if the aspect ratio, height divided by width, of a structurebecomes too large. Pattern collapse can be associated with mechanicalinstability of a high aspect ratio structure such that forces, e.g.,surface tension, associated with the processing steps distort thestructural elements. Low aspect ratio structures are more stable withrespect to potential distorting forces. With the patternable coatingmaterials described herein, due to the ability to process effectivelythe structures with thinner layers of coating material, improvedpatterning can be accomplished without the need for high aspect ratiopatterned coating material. Thus, very high resolution features havebeen formed without resorting to high aspect ratio features in thepatterned coating material.

The resulting structures can have sharp edges with very low line-widthroughness. In particular, in addition to the ability to reduceline-width roughness, the high contrast also allows for the formation ofsmall features and spaces between features as well as the ability toform very well resolved two-dimensional patterns (e.g., sharp corners).Thus, in some embodiments, adjacent linear segments of neighboringstructures can have an average pitch of no more than about 60 nm, insome embodiments no more than about 50 nm and in further embodiments nomore than about 40 nm. Pitch can be evaluated by design and confirmedwith scanning electron microscopy (SEM), such as with a top-down image.As used herein, pitch refers to the spatial period, or thecenter-to-center distances of repeating structural elements. Featuredimensions of a pattern can also be described with respect to theaverage width of the feature, which is generally evaluated away fromcorners or the like. Also, features can refer to gaps between materialelements and/or to material elements. In some embodiments, averagewidths can be no more than about 30 nm, in further embodiments no morethan about 25 nm, and in additional embodiments no more than about 20nm. Average line-width roughness can be no more than about 3.0 nm, andin further embodiments from about 1.5 nm to about 2.5 nm. Evaluatingline-width roughness is performed by analysis of top-down SEM images toderive a 3σ deviation from the mean line-width. The mean contains bothhigh-frequency and low-frequency roughness, i.e., short correlationlengths and long correlation lengths, respectively. The line-widthroughness of organic resists is characterized primarily by longcorrelation lengths, while the present inorganic coating materialsexhibit significantly shorter correlation lengths. In a pattern transferprocess, short correlation roughness can be smoothed during the etchingprocess, producing a much higher fidelity pattern. A person of ordinaryskill in the art will recognize that additional ranges of pitch, averagewidths and line-width roughness within the explicit ranges above arecontemplated and are within the present disclosure.

Further Processing of Patterned Coating Material

After forming a patterned coating material, the coating material can befurther processed to facilitate formation of the selected devices.Furthermore, further material deposition, etching and/or patterninggenerally can be performed to complete structures. The coating materialmay or may not ultimately be removed. The quality of the patternedcoating material can in any case be carried forward for the formation ofimproved devices, such as devices with smaller foot prints and the like.

The patterned coating material forms openings to the underlyingsubstrate, as shown for example in FIGS. 3 and 4 . As with conventionalresists, the patterned coating material forms an etch mask which can beused to transfer the pattern to selectively remove an underlying thinfilm. Referring to FIG. 7 , underlying thin film 103 is patternedleaving features 152, 154, 156 respectively under condensed regions 110,112, 114. Compared with conventional polymer resists, the materialsdescribed herein can provide significantly greater etch resistance.Similar processing can be undertaken with the mask pattern shown inFIGS. 5 and 6 with corresponding shifting of the patterned structuresthat follow directly from the alternative mask pattern.

Alternatively or additionally, the deposition of a further materialaccording to the mask pattern can alter the properties of the underlyingstructure and/or provide contact to the underlying structure. Thefurther coating material can be selected based on the desired propertiesof the material. In addition, ions can be selectively implanted into theunderlying structure through openings in the mask, as the density of thepatterned inorganic coating material can provide a high implantresistance. In some embodiments, the further deposited material can be adielectric, a semiconductor, a conductor or other suitable material. Thefurther deposited material can be deposited using suitable approaches,such as solution based approaches, chemical vapor deposition (CVD),sputtering, physical vapor deposition (PVD), or other suitable approach.

In general, a plurality of additional layers can be deposited. Inconjunction with the deposition of a plurality of layers, additionalpatterning can be performed. Any additional patterning, if performed,can be performed with additional quantities of the coating materialsdescribed herein, with polymer-based resists, with other patterningapproaches or a combination thereof.

As noted above, a layer of coating (resist) material followingpatterning may or may not be removed. If the layer is not removed, thepatterned coating (resist) material is incorporated into the structure.For embodiments in which the patterned coating (resist) material isincorporated into the structure, the properties of the coating (resist)material can be selected to provide for desired patterning properties aswell as also for the properties of the material within the structure.

If it is desired to remove the patterned coating material, the coatingmaterial functions as a conventional resist. The patterned coatingmaterial is used to pattern a subsequently deposited material prior tothe removal of the resist/coating material and/or to selectively etchthe substrate through the spaces in the condensed coating material. Thecondensed coating material can be removed using a suitable etchingprocess. Specifically, to remove the condensed coating material, a dryetch can be performed, for example, with a BCl₃ plasma, Cl₂ plasma, HBrplasma, Ar plasma or plasmas with other appropriate process gases.Alternatively or additionally, a wet etch with, for example, an aqueousacid or base, such as HF(aq), or buffered HF(aq)/NH₄F or oxalic acid canbe used to remove the patterned coating material. Referring to FIG. 8 ,the structure of FIG. 8 is shown after removal of the coating material.Etched structure 150 comprises substrate 102 and features 152, 154, 156.

The metal oxo/hydroxo based coating materials are particularlyconvenient for performing multiple patterning using a thermal freezeprocess, as described generally with conventional resists in P.Zimmerman, J. Photopolym. Sci. Technol., Vol. 22, No. 5, 2009, p. 625. Adouble patterning process with a “thermal freeze” is outlined in FIG. 9. In the first step, the coating material is formed into a pattern 160on substrate 162 using a lithographic process and development asdescribed with respect to FIGS. 3 and 4 . A heating step 164 isperformed to remove solvent and condense the coating material, which mayor may not involve full oxide formation. This heating step is equivalentto the post-development heating step described in the Developmentsection above. This “thermal freeze” process makes the coating materialinsoluble to a subsequent deposition of a second layer of the coatingmaterial. A second lithographic and development step 166 is performed toform a double patterned structure 168 on substrate 162. After an etchstep 170, the product double patterned structure 172 is formed. Notethat it is straightforward to extend this process to multiple coat andpattern steps, and such extensions are contemplated and are within thepresent disclosure. With respect to multiple patterning, a significantdifference between the inorganic coating materials described herein andconventional organic resists is that organic resists remain soluble inconventional resist casting solvents even after a thermal bake. Theresist materials described herein can be condensed with a thermal bakesuch that they are not soluble in organic solvents and subsequentcoating layers can be applied.

EXAMPLES Example 1 Preparation of Precursor Solutions

This example described preparation of precursor solutions for thedeposition of Tin based organometallic compositions for the formation ofa radiation resist coating.

A resist precursor solution was prepared by adding 0.209 g monobutyltinoxide hydrate (BuSnOOH) powder (TCI America) to 10 mL of4-methyl-2-pentanol. The solution was placed in a closed vial andallowed to stir for 24 h. The resulting mixture was centrifuged at 4000rpm for 15 minutes, and filtered through a 0.45 μm PTFE syringe filterto remove insoluble material.

Solvent evaporation and calcination of this sample at 600° C. revealed atin concentration of 0.093 M on the basis of SnO₂ residual mass. Dynamiclight scattering (DLS) analysis with a Möbius apparatus (WyattTechnology) of the precursor solution (FIG. 10 ) is consistent with amonomodal distribution of particles with a mean diameter of ˜2 nm,consistent with the reported diameter (Eychenne-Baron et al.,Organometallics, 19, 1940-1949 (2000)) of dodecameric butyltin hydroxideoxide polyatomic cations. Thus, the results are consistent with clusterformation within the non-aqueous solutions.

Example 2 Resist coating, Film Processing, Negative Tone Imaging

This example demonstrates the formation of a resist pattern based onnegative tone imaging based on e-beam exposure or extreme ultravioletexposure.

Silicon wafers (25×25 mm square) with a native-oxide surface were usedas substrates for thin-film deposition. Si substrates were treated witha 10 minute cycle in an Ultra-Violet Ozone cleaning system beforedeposition. The resist precursor solution from Example 1 was thenspin-coated on the substrate at 4500 rpm for 30 s and baked on ahotplate for 2 min at 100° C. to remove residual solvent. Film thicknessfollowing coating and baking was measured via ellipsometry to be ˜22 nm.

A first substrate coated with a resist film was exposed to a 30-kVelectron-beam rastered to form a pattern with a dose of 1100 μC/cm². Thepatterned resist and substrate were then subjected to a post-exposurebake (PEB) for 2 min at 150° C. The exposed film was then dipped in apolar organic solvent for 30 seconds and rinsed with in DI H₂O to form anegative tone image with unexposed portions of the coating removed. Afinal 5-min hotplate bake at 200° C. was performed after development.FIG. 11 exhibits SEM images of 18-nm lines on a 36-nm pitch in resistfilm developed in 4-methyl-2-pentanol (a), ethyl lactate (b), propyleneglycol monomethyl ether (PGMEA) (c), and n-butyl acetate (d). Anothersubstrate was prepared with the identical precursor solution andcoating/baking processes were used prior to exposure to extremeultraviolet radiation, which is similarly suitable for high-resolutionpatterning. A pattern of 22 and 18-nm lines on 44 and 36-nm pitches,respectively, were exposed on the resist using projection with anumerical aperture of 0.3 operating at 13.5 nm wavelength and an imagingdose of 101 mJ/cm². After a 2-min, 165° C. hotplate PEB, the film wasdeveloped by immersion in PGMEA, rinsed with DI H₂O, and baked a finaltime for 5 min at 200° C. Negative images of the well-resolvedline-space patterns are shown in FIG. 12 .

The chemical contrast generated upon radiation exposure that induces thepolarity change revealed in development rate contrast and resist imagingperformance is clearly illustrated with Fourier transform infrared(FTIR) spectroscopy. Transmission mode FTIR spectra of a butlytinhydroxide oxide resist film spin-coated on an un-doped Silicon waferfrom a tetrahydrofuran (THF) solvent were collected as a function ofexposure dose with a 30 kV electron beam. Analysis of several absorptionpeaks corresponding to Alkyl C-H stretching modes from 2800-2900 cm⁻¹indicates a consistent decrease in the concentration of the alkyl ligandas a function of dose (FIG. 13 ).

Example 3 Positive Tone Imaging

This example demonstrated the formation of a positive tone image usingthe resist solution from Example 1.

Another substrate was coated with a resist film deposited from anidentical precursor solution from Example 1 and baked on a hotplate at150° C. for 2 min. The based wafer with the resist coating was exposedwith an electron beam at 30 kV with a dose of 511 μC/cm², followed by a2-min, 150° C. post exposure bake. Positive tone imaging was achieved bydeveloping the exposed resist film in an aqueous base such as 2.38%tetramethyl ammonium hydroxide (TMAH). Immersion in 2.38% TMAH etchedthe exposed resist, developing the 30-nm (60 nm pitch) lines shown theSEM image in FIG. 14 .

Example 4 Resist Stability

This example demonstrates resist precursor stability by consistentimaging performance of a resist precursor solution and coated filmfollowing aging. A resist precursor solution prepared as previouslydescribed in Example 1 was applied via spin coating to a pair of wafersubstrates, which were baked on a hotplate for 2 min at 100° C. Aportion of the precursor solution was retained in a sealed vial andstored with one of the coated substrates (first substrate) in the dark,at uncontrolled room-temperature (20-30° C.) under an atmosphericambient. Immediately following coating, the second substrate with aresist film was successively patterned with a 30-kV electron beam, bakedat 150° C. for 2 min, developed for 30 s in PGMEA, rinsed, and hardbaked at 200° C. for 2 min. An SEM image of the resulting patternedsecond substrate is shown in FIG. 15A. This exposure and developmentprocess was repeated on the stored first substrate with the resist film39 days later. An SEM image of the patterned first substrate is shown inFIG. 15B. Likewise, the retained portion of the original precursorsolution was used on the same day after 39 days of storage to coat athird wafer substrate with a resist film, which was immediatelyprocessed, exposed, and developed identically to the first twosubstrates. An SEM image of the patterned third substrate is shown inFIG. 15C. The imaging performance of the three resist films on the same36 nm pitch and 18 nm line width is found to be functionally identical,with no observable degradation in image fidelity, LWR, or sensitivityafter aging of the coated resist film or precursor solution over a39-day period.

Example 5 Radiation Sensitivity Modulation Based On Organic LigandSelection

This example demonstrates that modulation in resist radiationsensitivity is observed by selecting appropriate organic ligands.

Divinyltin dichloride (Alpha Aesar) was dissolved in PGMEA to aconcentration of 0.1 M. A 15 mL quantity of this solution was placed ina separatory funnel, to which was added 7.31 mL of 0.4 M NaOH (aq).Immediately following NaOH addition, the vessel was shaken thoroughlyfor ˜1 minute, and the resulting emulsion was allowed to separate for˜24 h. During this period, a light flocculate formed at the phaseinterface between the two media was observed to dissipate, and two clearphases were obtained. The lower aqueous phase was removed from thefunnel and the upper, PGMEA, phase was shaken over a 4A molecular sieve(Mallinkrodt, Grade 514) for ˜5 minutes to remove residual water.Solvent evaporation and calcination of an aliquot of the sievedcomposition disclosed a tin concentration of 0.1 M on the basis of theresidual mass SnO₂.

The preceding divinyltin hydroxide solution in PGMEA followingseparation and sieving was directly spin-cast on a silicon wafer at 1250rpm and subjected to a 100° C. hotplate bake for 2 min. Ellipsometricmeasurement post-baking indicated a resist film thickness of ˜16 nm. Theresist film was exposed with 30 kV electron beam at a dose of 75 μC/cm²followed by a second hotplate bake at 100° C., and development in PGMEA.An SEM image of a negative tone line/space pattern on a 100 nm pitch isdisplayed in FIG. 16 . Note that the electron beam dose used to generateFIG. 16 was significantly less than used in Examples 2 and 3.

Transmission-mode FTIR spectra were collected on similar resist filmsdeposited from an ethyl acetate solvent on undoped silicon wafers as afunction of dose. The relative IR absorption as a function of electronbeam dose is plotted in FIG. 17 . Based on an analysis of the area of anabsorption peak consistent with the vinyl C-H stretch centered at ˜30551/cm, a drop in the area indicates the loss of vinyl groups as tinligands on exposure that is much more rapid and comprehensive withrespect to dose than the loss of alkyl ligands in the butyltin hydroxideoxide case shown in FIG. 13 .

Example 6 Organotin Oxo-Carboxylate Resist

This example demonstrates the effectiveness of a radiation resist formedwith alkyl and carboxylate ligands for tin ions.

A resist precursor solution was prepared by dissolving dibutyltindiacetate (Alfa-Aesar) in n-propanol to a final concentration of 0.025M. The solution was then filtered through a 0.45 μm PTFE syringe filter,and spin cast on a silicon wafer substrate rotated at 3000 rpm for 30 s.The coated film was then baked for 2 min at 60° C. to remove residualsolvent. During casting and baking the dibutyltin diacetate is partiallyhydrolyzed by atmospheric water, converting from a volatile molecularliquid carboxylate into a solid organotin oxo carboxylate. Ellipsometricmeasurements indicated a resist film thickness of ˜22 nm.

Subsequent exposure of the film to a 30 kV electron beam rastered toform a pattern at a dose of 1500 μC cm⁻² was followed by a 60° C.hotplate PEB, and immersion in PGMEA for 30 s to develop the pattern byetching unexposed material. A final hardbake at 100° C. for 5 min wasperformed prior to SEM imaging. FIG. 18 contains an electron micrographof the resulting negative tone line/space pattern on a 32-nm pitch.

Generation of chemical contrast in the foregoing material upon radiationexposure via electron-beam may be observed by using transmission FTIRspectroscopy as illustrated in FIG. 19 . The transmission spectra of anorganotin oxo-carboxylate thin-film deposited on an un-doped siliconwafer and baked at 50° C. for 2 min was collected before and afterexposure to a 30 kV electron beam (800 μC cm⁻²). As with simpleorganotin oxo hydroxides, a strong decrease in the absorption peaksattributed to hydrocarbon C—H stretching and bending modes (2957, 2924,2858, 1391, and 1331 cm⁻¹) is observed, confirming loss of alkyl ligandson exposure. Also readily apparent and unique to the carboxylate is thesignificant reduction in the absorbance centered at 1605 cm⁻¹,attributed to decomposition of carboxylate ligands and attendantreduction in carbonyl C═O absorption on exposure.

The embodiments above are intended to be illustrative and not limiting.Additional embodiments are within the claims. In addition, although thepresent invention has been described with reference to particularembodiments, those skilled in the art will recognize that changes can bemade in form and detail without departing from the spirit and scope ofthe invention. Any incorporation by reference of documents above islimited such that no subject matter is incorporated that is contrary tothe explicit disclosure herein.

What is claimed is:
 1. An article comprising: a substrate with a surfaceand a patterned coating comprising a first material at selected regionsalong the surface and absent at other regions along the surface, thefirst material comprising a metal oxo-hydroxo network and organicligands with metal cations having organic ligands with metal carbonbonds and/or with metal carboxylate bonds, wherein alternatively thefirst material is soluble in at least some organic liquids or the firstmaterial is soluble in aqueous bases and/or aqueous acids.
 2. Thearticle of claim 1 wherein the metal oxo-hydroxo network has both M-O—Hlinkages and M-O-M linkages.
 3. The article of claim 1 wherein thesubstrate surface is exposed at the regions of the substrate where thefirst material is absent.
 4. The article of claim 1 wherein the metalcomprises tin, antimony, indium or a combination thereof and wherein theorganic ligand forms a radiation sensitive metal carbon bond and whereinthe ligand forming the metal carbon bond comprises an alkyl ligand,alkenyl ligand, aryl ligand, or a combination thereof, each ligandcontaining 1 to 16 carbon atoms and/or wherein the organic ligands forma radiation sensitive metal carboxylate bond and wherein the metalcarboxylate bond is formed by an alkyl carboxylate ligand, alkenylcarboxylate ligand, aryl carboxylate ligand or a combination thereof,each ligand having 1 to 16 carbon atoms.
 5. The article of claim 1wherein the organic ligands with metal carbon bonds comprise branchedalkyl ligands.
 6. The article of claim 1 wherein the organic ligandswith metal carbon bonds comprise t-butyl ligands.
 7. The article ofclaim 1 wherein the metal comprises tin, antimony, indium or acombination thereof, and a combination of different alkyl ligands arebound to the metal.
 8. The article of claim 1 wherein the metalcomprises tin and the first material comprises Sn—O—H and Sn—O—Sn bondsand radiation sensitive Sn—C bonds and/or radiation sensitiveSn—carboxylate bonds.
 9. The article of claim 1 wherein the firstmaterial comprises one or more compositions with tin and non-tin metalsin a blend.
 10. The article of claim 1 wherein the first material isfree of peroxide ligands.
 11. The article of claim 1 wherein thepatterned coating comprises features with an average pitch of no morethan about 60 nm, average widths of no more than about 30 nm, and/oraverage line-width roughness of no more than about 3.0 nm.
 12. Thearticle of claim 1 wherein the substrate comprises a semiconductorwafer.
 13. The article of claim 1 wherein the organic liquids comprisean aromatic compound, an ester, an alcohol, a ketone, an ether, or acombination thereof, optionally with up to 10% additive.
 14. The articleof claim 1 wherein the wherein the aqueous bases comprise a quaternaryammonium hydroxide composition, optionally with up to 10% additive. 15.The article of claim 1 wherein the patterned coating further comprises asecond material along the surface of the substrate at regions where thefirst material is absent and wherein the article can be alternativelysubjected to positive tone imaging or negative tone imaging.
 16. Thearticle of claim 15 wherein the second material comprises a metaloxo-hydroxo network and organic ligands with metal cations havingorganic ligands with metal carbon bonds and/or with metal carboxylatebonds, wherein the oxo-hydroxo network of the second material has bothM-O—H linkages and M-O-M linkages.
 17. The article of claim 16 whereinthe metal oxo-hydroxo network of the second material comprises the sameorganic ligands and metal cations as the metal oxo-hydroxo network ofthe first material and wherein the metal oxo-hydroxo network of thefirst material has a lower carbon to metal ratio than the metaloxo-hydroxo network of the second layer.
 18. The article of claim 15wherein the first material is soluble in aqueous bases and wherein thesecond material is effectively soluble in at least some organic liquids.19. The article of claim 15 wherein the first material and the secondmaterial are free of peroxide ligands.
 20. The article of claim 3further comprising a layer of a third material over the first patternedcoating, wherein the third material comprises a metal oxo-hydroxonetwork and organic ligands with metal cations having organic ligandswith metal carbon bonds and/or with metal carboxylate bonds, and whereinthe first patterned coating is not soluble in at least some organicliquids.